Field of the Invention
The present invention relates to an engine breather apparatus configured to lead blow-by gas in a crank chamber to an intake system.
Description of the Related Art
Patent Document 1 (Japanese Patent Laid-Open No. 2000-45747) discloses a breather apparatus for a four-stroke OHV engine, where a breather chamber is formed on a top face of a cylinder block along substantially half a circumference of a cylinder bore, a cylinder and a crankcase are constructed integrally in the cylinder block, the cylinder bore extends horizontally in the cylinder, and the crankcase makes up a crank chamber.
However, with the breather apparatus described in Patent Document 1, volume and shape of the breather chamber may be restricted depending on the type and arrangement of valve device, which could disable the breather apparatus from delivering sufficient gas/liquid separation performance. For example, in an engine of the form (vertical form) in which a crankshaft is placed in a vertical direction, if the valve device is placed on a side of the cylinder rather than below the cylinder, the valve device may make it impossible to secure a sufficient volume of the breather chamber, which could lead to degradation in the gas/liquid separation performance of the breather apparatus.